This invention is in the field of antiinflammatory pharmaceutical agents and specifically relates to prodrugs of compounds which selectively inhibit cyclooxygenase-2.
The use of non-steroidal antiinflammatory drugs (NSAIDs) in treating pain and the swelling associated with inflammation also produce severe side effects, including life threatening ulcers. The recent discovery of an inducible enzyme associated with inflammation (xe2x80x9cprostaglandin G/H synthase IIxe2x80x9d or xe2x80x9ccyclooxygenase-2 (COX-2)xe2x80x9d) provides a viable target of inhibition which more effectively reduces inflammation and produces fewer and less drastic side effects.
Compounds which selectively inhibit cyclooxygenase-2 have been described. U.S. Pat. No. 5,380,738 and WO94/27980 describe oxazoles which selectively inhibit cyclooxygenase-2. U.S. Pat. No. 5,344,991 describes cyclopentenes which selectively inhibit cyclooxygenase-2. U.S. Pat. No. 5,393,790 describes spiro compounds which selectively inhibit cyclooxygenase-2. WO94/15932 describes thiophene and furan derivatives which selectively inhibit cyclooxygenase-2. WO94/13635 and WO94/20480 describe compounds which selectively inhibit cyclooxygenase-2. WO95/15316 describes pyrazolyl sulfonamide derivatives which selectively inhibit cyclooxygenase-2. However, in some circumstances, prodrugs of antiinflammatory compounds are advantageous, especially where the prodrugs have increased water solubility or delayed onset of action.
Substituted sulfonamides have been described. Pyrazolyl-sulfonylureas have been described as having possible hypoglycemic activity [H. Faid-Allah and H. Mokhtar, Ind. J. Chem, 27, 245 (1988)]. JP 1,045,374 describes water soluble tetrazolium compounds useful in assays for determining reducing substances. D. Mukerjee et. al. [Acta. Pharma. Jugosl., 31, 151 (1981)] describe tetrazolium sulfonamides as antiviral agents. JP 4,277,724 describes triphenyl pyrazolines as nonlinear optical material. JP 5,323,522 describes the use of heterocyclic compounds in black and white photographic material. U.S. Pat. No. 5,389,635 describes substituted imidazoles as angiotensin II antagonists. U.S. Pat. No. 5,387,592 describes substituted benzimidazole derivatives as angiotensin II antagonists. G. Dorofeenko et. al. [Khim. Farm. Zh., 16, 920 (1982)] describe pyridinium salts as antiviral agents. U.S. Pat. No. 5,338,749 describes diaryl-substituted heterocyclyl compounds as antiarthritis agents. WO94/26731 describes thiophene compounds which selectively inhibit cyclooxygenase-2. WO95/00501 describes compounds which selectively inhibit cyclooxygenase-2, and specifically, 3-(4-(trifluoroacetylaminosulfonyl)phenyl)-2-(4-fluorophenyl)thiophene is described. T. Ivanov [Mh. Chem., 97, 1499 (1966)] describes the preparation of diarylindone derivatives as possible indicators, and 2-(4-(N-methylaminosulfonyl)phenyl)-3-phenylindone is specifically described.
J. Larsen and H. Bundgaard [Int. J. Pharmaceutics, 37, 87 (1987)] describe the evaluation of N-acylsulfonamides as potential prodrug derivatives. J. Larsen et. al. [Int. J. Pharmaceutics, 47, 103 (1988)] describe the evaluation of N-methylsulfonamides as potential prodrug derivatives.
There currently exists a need for compounds suitable for use in antiinflammatory compositions which can readily penetrate across biological membranes to provide improved drug absorption. Further, there currently exists a need for compounds which are more soluble and stable. The compounds of the present invention are found to show usefulness as prodrugs.
The present invention provides a compound of Formula (I): 
or a pharmaceutically-acceptable salt thereof wherein:
A is a ring substituent selected from the group consisting of heterocyclyl, heteroaryl, cycloalkenyl and aryl, wherein A is optionally substituted at a substitutable position with one or more radicals independently selected at each occurrence from the group consisting of alkylcarbonyl, formyl halo, alkyl, haloalkyl, oxo, cyano, nitro, carboxyl, alkoxy, aminocarbonyl, alkoxycarbonyl, carboxyalkyl, cyanoalkyl, hydroxyalkyl haloalkylsulfonyloxy, alkoxyalkyloxyalkyl, carboxyalkoxyalkyl, cycloalkylalkyl, alkenyl, alkynyl, heterocyclyloxy, alkylthio, cycloalkyl, aryl, heterocyclyl, cycloalkenyl aralkyl, heterocyclylalkyl, alkylthioalkyl, arylcarbonyl aralkylcarbonyl, aralkenyl, alkoxyalkyl, arylthioalkyl, aryloxyalkyl, aralkylthioalkyl, aralkoxyalkyl, alkoxycarbonylalkyl, aminocarbonylalkyl, alkylaminocarbonyl N-arylaminocarbonyl, N-alkyl-N-arylaminocarbonyl, alkylaminocarbonylalkyl, alkylamino, N-arylamino, N-aralkylamino, N-alkyl-N-aralkylamino, N-alkyl-N-arylamino, aminoalkyl, alkylaminoalkyl, N-arylaminoalkyl, N-aralkylaminoalkyl, N-alkyl-N-aralkylaminoalkyl, N-alkyl-N-arylaminoalkyl, aryloxy, aralkoxy, arylthio, aralkylthio, alkylsulfinyl, alkylsulfonyl, aminosulfonyl, alkylaminosulfonyl N-arylaminosulfonyl, arylsulfonyl and N-alkyl-N-arylaminosulfonyl;
R1 is selected from the group consisting of heteroaryl, heterocyclyl, cycloalkyl, cycloalkenyl and aryl, wherein R1 is optionally substituted at a substitutable position with one or more radicals independently selected at each occurrence from the group consisting of alkyl, haloalkyl cyano, carboxyl, alkoxycarbonyl, hydroxyl, hydroxyalkyl, haloalkoxy, amino, alkylamino, arylamino, nitro, alkoxyalkyl, alkylsulfinyl, halo, alkoxy and alkylthio;
R2 and R3 are independently selected from the group consisting of hydrido, alkyl, alkylcarbonyl, hydroxyalkyl, heterocyclyl heteroaryl, monosaccharide, disaccharide, polysaccharide, alkylphosphate, acyloxyalkyl, alkylaminocarbonyl, alkoxyaralkyl and carboxyalkyl, wherein R3 is optionally substituted at a substitutable position with one or more radicals independently selected at each occurrence from the group consisting of alkylcarbonyl, formyl, halo, alkyl, haloalkyl, oxo, cyano, nitro, carboxyl, alkoxy, aminocarbonyl, alkoxycarbonyl, carboxyalkyl, cyanoalkyl, hydroxyalkyl, haloalkylsulfonyloxy, alkoxyalkyloxyalkyl, carboxyalkoxyalkyl, cycloalkylalkyl, alkenyl alkynyl, heterocyclyloxy, alkylthio, cycloalkyl, aryl, heterocyclyl, cycloalkenyl, aralkyl, heterocyclylalkyl, alkylthioalkyl, arylcarbonyl, aralkylcarbonyl, aralkenyl, alkoxyalkyl, arylthioalkyl, aryloxyalkyl, aralkylthioalkyl, aralkoxyalkyl, alkoxycarbonylalkyl, aminocarbonylalkyl, alkylaminocarbonyl, N-arylaminocarbonyl, N-alkyl-N-arylaminocarbonyl, alkylaminocarbonylalkyl, alkylamino, N-arylamino, N-aralkylamino, N-alkyl-N-aralkylamino, N-alkyl-N-arylamino, aminoalkyl, alkylaminoalkyl, N-arylaminoalkyl, N-aralkylaminoalkyl, N-alkyl-N-aralkylaminoalkyl, N-alkyl-N-arylaminoalkyl, aryloxy, aralkoxy, arylthio, aralkylthio, alkylsulfinyl alkylsulfonyl, aminosulfonyl, alkylaminosulfonyl, N-arylaminosulfonyl, arylsulfonyl, and N-alkyl-N-arylaminosulfonyl;
wherein at least one of R2 and R3 is other than hydrido;
wherein R2 is other than alkyl, carboxyalkyl or alkylcarbonyl when R3 is hydrido; and
wherein R3 is other than alkyl, carboxyalkyl or alkylcarbonyl when R2 is hydrido;
or, R2 and R3 are taken together along with the nitrogen to which they are attached to form a three to seven membered saturated, partially unsaturated or unsaturated heterocyclic ring and may optionally be substituted at a substitutable position with one or more R5 radicals, wherein the R5 radicals are independently selected at each occurrence from the group consisting of alkylcarbonyl, formyl, halo, alkyl, haloalkyl, alkylphosphate, phosphate, oxo, cyano, nitro, alkoxy, aminocarbonyl, alkoxycarbonyl, carboxyalkyl, cyanoalkyl, hydroxyalkyl, haloalkylsulfonyloxy, alkoxyalkyloxyalkyl, carboxyalkoxyalkyl, cycloalkylalkyl, alkenyl, alkynyl, heterocyclyloxy, alkylthio, cycloalkyl, aryl, heterocyclyl, cycloalkenyl, aralkyl, heterocyclylalkyl, alkylthioalkyl, arylcarbonyl aralkylcarbonyl, aralkenyl, alkoxyalkyl, arylthioalkyl, aryloxyalkyl, aralkylthioalkyl, aralkoxyalkyl, alkoxycarbonylalkyl, aminocarbonylalkyl, alkylaminocarbonyl, N-arylaminocarbonyl, N-alkyl-N-arylaminocarbonyl, alkylaminocarbonylalkyl, alkylamino, N-arylamino, N-aralkylamino, N-alkyl-N-aralkylamino, N-alkyl-N-arylamino, aminoalkyl, alkylaminoalkyl, N-arylaminoalkyl, N-aralkylaminoalkyl, N-alkyl-N-aralkylaminoalkyl, N-alkyl-N-arylaminoalkyl, aryloxy, aralkoxy, arylthio, aralkylthio, alkylsulfinyl, alkylsulfonyl, aminosulfonyl, alkylaminosulfonyl, N-arylaminosulfonyl, arylsulfonyl and N-alkyl-N-arylaminosulfonyl; and
R4 is selected from hydrido and fluoro;
wherein R5 is other than methyl when A is isoxazole, R1 is phenyl and R2 and R3 are taken together to form a pyrrole ring.
The present invention also provides a pharmaceutical composition comprising a therapeutically-effective amount of a compound of Formula (I), and a method of treating a cyclooxygenase-2 mediated disease such as inflammation or an inflammation-related disorder in a subject.